Moving stairways



.June 4, 1957 w. STELZER 2,794,531

- MOVING STAIRWAYS I Filed Aug. 12, 1953 2 Sheets-Sheet l IIIIIIIIIIII I ll L k izgai INVENTOR.

June 4, 1957 'w. STELZER 2,

- MOVING STAIRWAYS Filed Aug. 12, 1953. 2 Sheets-Sheet 2 INVENTOR.

I I! llllI'lIIIIIlI/Ifllll/l/ll United States Patent C MOVING STAIRWAYS William Stelzer, Bloomfield Hills, Mich.

Application August 12, 1953, Serial No. 373,811

8 Claims. (Cl. 198-46) The invention relates to moving stairways and more particularly to moving stairways where the treads or steps reciprocate.

The object of the invention is to produce a novel power operated means to assist persons in ascending and descending stairs, and particularly to produce a device that is safe in use and less expensive to manufacture than present known moving stairways so that it lends itself for use in private homes.

Another object is to construct a stairway comprising a set of fixed steps and an adjacent set of steps reciprocating vertically or on an inclined plane, so that the person using the stairway may ascend or descend by alternately stepping from a tread of the fixed stair to a tread of the reciprocating stair, the manual exertion being the same as walking on a level floor.

A further object of this invention is to construct a stairway with a pair of oppositely reciprocating adjacent stairs so that the ascension or descension can be accomplished in less time, the user stepping alternately from one step to the adjacent step when it is on the same level.

The invention also aims to provide simple means to arrest the stairs when not power driven in a position where they can be used as conventional stairs.

Other objects and advantages of this invention will be apparent from the following description considered in connection with the accompanying drawings submitted for the purpose of illustration and not to define the scope of the invention, reference being bad for that purpose to the subjoined claims. In the drawings, wherein similar reference characters refer to similar parts throughout the several views:

Fig. 1 is a sectional side elevation of a moving stairway embodying my invention, the section being taken on lines 1-1 of Fig. 3;

Fig. 2, a diagram of the electrical circuit for energizing the power means of the construction illustrated in Fig. 1;

Fig. 3, a section taken on lines 3-3 of Fig. 1;

Fig. 4, a perspective view of the same construction, the movable handrail having been removed;

Fig. 5, a sectional side elevation of a modified form of the invention, the section being taken along lines 55 of Fig. 6;

Fig. 6, a section taken on lines 66 of Fig. 5;

Fig. 7, a sectional side elevation of a further modification; and

Fig. 8, a sectional side elevation showing yet another form of the invention.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of elements illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practised or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of descrlption and not limitation.

Describing the invention now in detail and referring to Figs. 1-4, there is shown a fixed stair 1 comprising stringers 2 and 3 and steps having treads 4, leading from a lower floor level 5 to a higher floor level 6. Juxtaposed with this fixed stair is a reciprocable stair denoted in its entirety by numeral 7 and comprising a plurality of steps having treads 8 rigidly secured to trusses or stringers 9 and 10, the latter carrying a pair of balusters 11 supporting a handrail 12. These elements constituting stair 7 thus form a rigid unit arranged alongside stair 1 but movably supported on double arms 13 and 14 pivoted on shafts 15 secured to a fixed frame 16 or other structural member of the building in which the stairway is installed. The outer ends of arms 13 and 14 are pivotally secured to brackets 17 and 18 respectively, extending from the risers of the steps 8. Levers 13 and 14, together with structural side members 16 and stair 7, form a parallelogram so that all points of stair 7 travel at equal velocity, the movement being approximately parallel with the slope of the stairs. The preferably comb shaped edge 19 of step 8' moves along a curved plate 20 secured to the floor supporting structure of upper level 6. The bottom tread 21 is pivotally secured to the movable stair at 22, a lug 23 extending from the tread upwardly resting against the riser to hold tread 21 horizontally as shown when in use, but yielding when an object is accidentally placed under it, thus preventing accidental injury or damage. Stringers 2 and 9 are of minimum height so as not to be an obstacle to a person using the stairs. Thus they do not extend to the nosings of the steps. To prevent a shearing action between adjacent steps of the two stairs, the corners are chamfered as at 24, shown in Fig. 4. For actuation of the moving stair a gear motor unit 25 supported on a cross-member 26 of frame 16 and having a crank 27 is connected by means of a telescoping connecting rod 28 to one of the arms of lever 14, reciprocating stair 7 to have a stroke slightly longer than the distance between nosings of the steps. Connecting rod 28 comprises a rod end 29 pivoted on shaft 30 and sliding in the bore of a cylinder or tappet 31 pivoted to the crank pin of crank 27 which is driven by drive shaft 32 revolving at reduced speed. At the bottom of the bore of cylinder 31 is a cushion 33, preferably of rubber or similar material. Connecting rod 28 acts only as a push rod to move stair 7 upwardly and to permit the arrest of the latter in the idle or locked position as shown, where the mechanical drive is at rest and lower arm 13 is held by a pawl or latch 34 engaging shaft 35, pawl 34 being pivoted at 36 to a bracket 37 attached to member 26 and operated by a solenoid 38 of the pull type. This solenoid is energized whenever the motor of the gear unit 25 is energized, as illustrated in the diagram in Fig. 2 where numeral 40 denotes switches with which the motor can be turned on or off at either floor level. Since there is only one moving stair, it may be desirable to counterbalance part of the weight of stair 7, for which purpose a counterweight 41 is shown.

In the modified construction shown in Figs. 5 and 6 a pair of inclined juxtaposed stairs 45 and 46 having steps 45 and 46' are reciprocated in opposite directions in an approximately vertical plane by two pairs of double armed levers 47 and 48 turning on shafts 49 supported by frame 50 secured to or forming part of the structure of the building, where 51 denotes the lower and 52 the upper floor level. The stairs are constructed similar to stair 7 already described, except that it is not necessary to chamfer the adjacent corners or ends of the nosings because in the vertical movement of the stairs there is no shearing action between oppositely moving steps. Fur:

V 3 thermore, the strings 53 do not extend above the treads so that there is no obstacle in stepping from one stair to the other. Each lever 48 consists of a straight arm 54 pivoted to a bracket 17 and an arm 55 being offset in the middle portion to be engagedat clevis pin 56by a .connecting rod 57 similar in construction as connecting rod 28 already described. These connecting rods 57 are actuated by a double throw crankshaft 58 driven by 'a gear motor 59 supported by a plate 60 fastened to the structure of floor 51. A bracket 61 extends from this plate to give a support to rod 49 intermediate levers 48. Each double armed lever 47 has a tie rod between its two amis engaged by a pawl or latch 62 pivoted to a fixed support at 63. and operated by. a pull type solenoid 64, the pawl being weighted in a manner to be biased into a latching position, as shown, where both stairs are held in their top positions and are at' rest. The purpose for this arrangement is to have both stairs aligned on an equal level when not mechanically driven so the two stairs can be used in the conventional manner acting as a single unit. An other reason is to enable the gear motor to start under no load. Where there is a plurality of superposed stairs as ina building of several stories I provide vertical posts 65 to the outside stringers of stairs 45 and 46.. The upper ends of the posts attach to the outside stringers of another set of stairs similar to the one shown except that the gear motor drive and the connecting rods are omitted.

The construction in Fig. 7 is based on the principle illustrated in Fig. 1 since there is a fixed stairway 70 leading from a lower level 71 to a higher level 72. Each step has an opening 73 through which slides pedestrial piston '74 having a piston rod 75 connected to a crosshead 76 whose ends are pivotally carried by a pair of parallel arms 77 and 78 revolubly supported on brackets 79 and 80 extending from the structure of the building. Arms 81 and 82 extending in bell crank fashion from levers 77 and.78 respectively are connected by a tie rod 83 and actuated by a connecting rod 84 pivotally connected to arms 82 and 85. Connecting rod 84 is actuated by a gearmotor in the same manner as connecting rod 28 in Fig. l is actuated. In order to let the piston-type steps come to rest where their tops are flush with the treads when not in use, connecting rod 84 is disengageable through the interposition of an electromagnet or clutch 86 engaged with armature plate 37. When the electromagnet is not energized the hollow rod 88 may slide back and 'forth without driving the pistons, whereby arm 78 rests on stop 89 and the pistons are in the retracted position as shown. The crank of the gear motor which drives rod 88 is so proportioned as to produce a piston stroke slightly higher 7 than the height of a step, the top position of a piston being shown by dotted lines at 90. The electrical diagram would be substantially the same as the one shown in Fig. 2, assuming that numeral 38 represents the electromagnet.

In another modification shown in Fig. 8 a plurality of steps 95 are arranged successively between a lower level 96 and a higher level 97 of the building, whereby the opening defined by lines 98, 99 and the building walls flanking the stairway forms a guide for the reciprocating steps, the latter having risers 100 slideable in relation to the tread of theadjacent step. Each step has a rigidly attached push rod 101 of successively increased length attached atthe lower end to a crankshaft 162 to be reciprocated vertically, the crankshaft being revolved slowly by mechanical means such as a gear motor. In the illustration shown, the distance from level 96 to the top of the firststep is equal to the rise of a step. The distance between the tops of the second and third steps is equal to two times the rise. The difference in length of one rod 101 and an adjacent rod is equal to the rise, or equal to the throw of crank 102.

In the operation of the moving stairway shown in Fig. 1 the ascending person first steps on step 21 when the latter has reached the lowest position and crank 27 is on dead center. After being elevated to the height of the first step the user steps oh the moving stair and onto the first step of the fixed stairway, pausing there to wait for the completion of the downstroke of moving stair 7 to step onto the second step of the moving stair to be lifted again to the height of another step. This procedure is repeated from one step to the next until the top level 6 is reached. In descending, an opposite procedure is used, by stepping on a moving step when it has reached the top position. When one of the switches is turned off, the gear motor and solenoid 38 are deenergized so that latch 34 engages rod to arrest the stair in the top position, as shown. The gearmotoris allowed to continue to run until its momentum is spent. If. a switch is turned on again to start the gear motor, solenoid 38 is also energized, but the force of the solenoid is not suflicient to lift latch 34 until the stair is lifted by power a slight amount at dead center of crank 25 when rod 29 bottoms on cushion 33. Thus the rest position of stair 7 is slightly below its top position, providing a smooth and noiseless start.

In the operation of the double moving stairway shown in Figs. 5 and 6 the person ascending first steps on the lowest step flush with level 51, and after ascending the height of one step steps on the adjacent step of the other stair, until the top level is reached. The user thus has nothing to do but to walk forwardly as on a level floor treading always on a rising step. After a short time a certain amount of skill is acquired in the use of the stairs, therefore they lend themselves ideally for use in private homes toserve a limited group of people. It is obvious that the stairs can be used for ascent as well as descent. The arresting mechanism works in the same way as that described in Fig. 1, latch 62 of each stair engaging lever 47 when solenoid 64 is deenergized, so that both stairs are held in the top position. When a switch is turned on and the gearmotor and solenoid are energized, latch 62 is retracted as soon as the pressure is relieved when rod 57 is placed under compression and the stair lifted a slight amount above the resting position shown. Thus first one stair is released and then the other.

The operation of the apparatus shown in Fig. 7 is similar to that shown in Fig. 1, since the user waits on a fixed step to step on a piston-type step as soon as the latter is in the lowest position, to be lifted to the next higher step,

waiting there until the piston on that step is flush with the latter, to then be boosted the height of another step.

In the construction shown in Fig. 8 the operation is more continuous. The ascending person first steps on the lowest step when the latter is flush with level 96, then continues to walk normally forward and timing the pace so as to tread on the next step whenever it has become level with the lower step. In this construction persons may ascend and descend simultaneously, passing each other, since the entire width of the stairway can be used, whereas in the construction illustrated in Fig. Sthe user must straddle the center of the two stairs, preferably al-'. ways placing the same foot on the same ascending stair; It will be observed that there is a certain amount of rocking motion in steps due to crankshaft 102. For this reason each step 95 is wider at the top, tapering towards the lower end so as not to bind or wedge on the side walls of the stairway. It will also be observed that in all the different embodiments, due to the action of the cranks, the speed of the steps is increased and decreased according to a sine curve so that the speed is reduced near the end of the stroke, giving the user ample opportunity to step onto the desired tread at the right time.

In another aspect of the invention, each fixed step in Fig. 1 may be considered as a station, where the user can get ofi the moving stairway. If the oblique stroke of the steps is increased substantially, this embodiment may be well suited for use in stores and similar public places.

Having thus described my invention, I claim:

1. An inclined fixed stairway having steps leading from a lower level to a higher level, a similarly inclined movable stair having steps similar to said fixed stairway, said stairway and stair being juxtaposed, means to guide said movable stair to move upwardly and downwardly where all points of said movable stair have equal velocity, said means to guide said movable stair comprising parallel links, each of said parallel links having a fixed pivoted end and a movable end pivotally connected to said movable stair so that the latter is guided to travel in an arcuate path, and power operated means operatively connected to force said movable stair upwardly approxi mately the height of one of said steps.

2. The construction as claimed in claim 1, and controllable means to arrest said movable stair in the top position of its stroke independently of the movement of said power operated means.

3. An inclined fixed stairway having steps leading from a lower level to a higher level, an inclined movable stair having steps similar to said fixed stairway, the latter and said stair being juxtaposed, parallel lever means to guide said movable stair to move upwardly and downwardly where all points of said movable stair travel at equal velocity, power-operated means operatively connected with said parallel lever means to reciprocate said movable stair, and a counterweight to counteract part of the weight of said movable stair.

4. The construction as claimed in claim 3, and a handrail carried by said movable stair to reciprocate with said stair.

5. The construction as claimed in claim 3, where said power-operated means comprises a gearmotor having a low speed output shaft, a crank mounted on said low speed output shaft, a connecting rod actuated by said crank and connected to said parallel lever means to force said stair upwardly so that the latter ascends and descends a height approximately equal to the height of one of said steps.

6. The construction as claimed in claim 5, where said crank is connected to said parallel lever means by a tappet-type connecting rod so that said stair is forced upwardly by power and descends by gravity.

7. An inclined stairway having at least one movable section comprising a plurality of steps, a plurality of spaced parallel links each having one end rotatable about a fixed pivotal axis and an opposite movable end pivotally secured to said movable section to guide the latter in an arcuate path about said fixed pivotal axis, and power operated means to move said movable section to reciprocate along said arcuate path where said power operated means including a power driven crank, a tappet type connecting rod actuated by said crank and operatively connected to actuate said links for forcing said movable section upwardly along said arcuate path, said tappet type connecting rod transmitting power only in the up ward movement of said movable section, whereby said movable section descends along said arcuate path only by gravity to follow the return movement of said crank.

8. The construction as claimed in claim 7, and a controllable latch mechanism operatively connected to arrest said movable section in the raised position.

Lorillard Dec. 19, 1905 Georgiev et al. Jan. 5, 1954 

